Vulkan: Migrate buffers between memory types to improve GPU performance (#4540)

* Initial implementation of migration between memory heaps

- Missing OOM handling
- Missing `_map` data safety when remapping
  - Copy may not have completed yet (needs some kind of fence)
  - Map may be unmapped before it is done being used. (needs scoped access)
- SSBO accesses are all "writes" - maybe pass info in another way.
- Missing keeping map type when resizing buffers (should this be done?)

* Ensure migrated data is in place before flushing.

* Fix issue where old waitable would be signalled.

- There is a real issue where existing Auto<> references need to be replaced.

* Swap bound Auto<> instances when swapping buffer backing

* Fix conversion buffers

* Don't try move buffers if the host has shared memory.

* Make GPU methods return PinnedSpan with scope

* Storage Hint

* Fix stupidity

* Fix rebase

* Tweak rules

Attempt to sidestep BOTW slowdown

* Remove line

* Migrate only when command buffers flush

* Change backing swap log to debug

* Address some feedback

* Disallow backing swap when the flush lock is held by the current thread

* Make PinnedSpan from ReadOnlySpan explicitly unsafe

* Fix some small issues

- Index buffer swap fixed
- Allocate DeviceLocal buffers using a separate block list to images.

* Remove alternative flags

* Address feedback

Ryujinx.Graphics.Vulkan/BufferState.cs

@@ -2,14 +2,14 @@
 
 namespace Ryujinx.Graphics.Vulkan
 {
-    readonly struct BufferState : IDisposable
+    struct BufferState : IDisposable
     {
         public static BufferState Null => new BufferState(null, 0, 0);
 
         private readonly int _offset;
         private readonly int _size;
 
-        private readonly Auto<DisposableBuffer> _buffer;
+        private Auto<DisposableBuffer> _buffer;
 
         public BufferState(Auto<DisposableBuffer> buffer, int offset, int size)
         {
@@ -29,6 +29,17 @@ namespace Ryujinx.Graphics.Vulkan
             }
         }
 
+        public void Swap(Auto<DisposableBuffer> from, Auto<DisposableBuffer> to)
+        {
+            if (_buffer == from)
+            {
+                _buffer.DecrementReferenceCount();
+                to.IncrementReferenceCount();
+
+                _buffer = to;
+            }
+        }
+
         public void Dispose()
         {
             _buffer?.DecrementReferenceCount();